Pipe-core.



J. W. BONTA.

Patented Dec. l9, I899.

P I P E C 0 R E.

(Application filed June 25, 1895. Renewed Oct. 21, 1899;)

(No Model.)

" INVENTOR WITNESSES:

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p UNITED STATES JAMES WVM. BONTA, OF \VAYNE, PENNSYLVANIA, ASSIGNOR TO THE BONTA GLASS PIPE AND CONDUIT COMPANY, OF SORANTON, PENNSYLVANIA.

PIPE-CORE.

SPECIFICATION forming part of Letters Patent No. 639,508, dated December 19, 1899. Application filed June 25,1895. Renewed October 21, 1899. fierial No 734,403. (No model.)

To all whom it may concern.-

Be it known that LJAMES WM. BONTA,a citizen of the United States,residing at Wayne, in the county of Delaware and State of Pennsyl- Vania, have invented certain new and useful Improvements in Pipe-Cores; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

My invention relates to certain improvements in cores used in the casting of pipe, and while specially applicable for use in the manufacture of glass pipes, as described in an application filed by me June 25,1895, Se rial No. 553,965, it may also be employed in the casting of pipe from molten iron or other metals.

The principal object of my invention is to construct a core which may be expanded and contracted to gradually change its diameter 2 5 to accommodate the shrinking of the glass or metal in cooling, the Various sections into which the core is divided being so arranged and constructed that when placed in either the expanded or the contracted position they will form a core circular in cross-section.

As the core herein described is intended to be used principally in the manufacture of glass pipe it is soshown in the drawings, although it will be understood that the core 5 Without other modification than the character of the mold may require may be used in connection with sand or loam molds for the casting of metallic or other pipe.

In the accompanying drawings, Figure 1 is an end elevation of a pipe-core constructed in accordance with my invention, showing it in position in a mold for casting glass pipe. Fig. 2 is a longitudinal sectional elevation of the same on the line 2 2, Fig. 1. Fig. 3 is a transverse sectional elevation on the line 3 3, Fig. 2. Fig. at is a similar View on the line 4 4, Fig. 2; and Fig. 5 is a partial transverse sectional elevation, on a somewhat larger scale, on the line 5 5, Fig. 2, showing the core 59 contracted.

Referring to the drawings, 0 represents a hollow shaft provided at each end with a plate 0, having a series of radial slots d, in which are guided the various sections D of the core proper. The plates 0 have also a second,series of radial slots 6, in which are guided a number of bars E, wedge-shaped in cross-section and adapted to fit between the adjacent edges of the sections D of the core, these edges being preferably inclined at an angle corresponding to the angle of the walls of the wedges, so that when the Wedges E and the sections D are forced out to the position which they assume when the core is expanded and in readiness for the casting operation the sides of the wedges will fit snugly against the inclined edges of the sections D and form a practically continuous core. The outer faces of the wedges D are curved on a line corresponding to the curvature of the sections D of the core, so that when in an expanded condition the core will have a continuous circular periphery.

Within the hollow shaft G is a central shaft C, having at or near each end a plate F, provided with two sets of cam-slots, one, 1, ar-' ranged near the periphery of the plate and the other, f, arranged near the shaft. The radial webs d of the core-sections D are provided with pins 9 which extend into the outer series of cam-slots f of the plate F, and the Web 6' of each of the wedge-bars E is provided with a similar pin g, each extending into one of the inner series ofcam-slotsf, so that as said plates F are turned the various sections and wedge-bars in the core will be drawn toward or forced from the center to contract or expand the core, as will be read ily understood.

It will be noticed that the inner series of cam-slots j, which act upon the wedge-bars E, are so formed as to act upon such wedge bars in advance of the operation of the outer series of slots f upon the sections D, of the core during the contractiomso that the wedge bars will be drawn in toward the center first and leave suflicient room for the subsequent movement of the sections D, the adjacent edges of the latter coming nearer and nearer together as the core is contracted until finally in the fully-contracted position the edges of the sections D meet and form a substantially circular and continuous core of a much less diameter than when expanded.

The difference in diameter between the expanded and contracted cores is preferably equal to the amount of contraction of the glass or metal during the cooling operation, as it is found that the glass or metal gradually shrinks during the setting and would be ruptured if the core Were a solid body.

In operation the core is placed within the mold in the fully-expanded position and the glass or metal is poured into the mold to form the pipe. During the setting and cooling of the glass or metal the latter of course will shrink to a considerable extent, and the operator, by turning the plates F by applying a lever to projecting pins 13 on said plates, gradually contracts the diameter of the core in accordance with the amount of shrinkage,

while at the same time when the core is fully contracted it will still present a practically continuous circular periphery to form a support'for the inner wall of the manufactured product and prevent the formation of ribs or ridges, which might otherwise occur if the sections of the core were separated to leave spaces into which the glass or metal might be forced.

Having thus described my invention-,what

I claim, and desire to secure by Letters Patent, isv 1. The combination, in a pipe-core, of a series of radially-guided sections, each section having a curved face and forming a segment of the core, a series of wedge-shaped fillingbars E adapted to fit between the sections, guides for the sections and the bars, and a revoluble cam-plate having two distinct series of cam-slots for effecting the radial movement of the sections and bars, substantially as specified.

2. The combination in a pipe-core, of the sections D having radially-arranged webs or ribs 01, a plate 0 having radial guiding-slots d for the reception of such webs or ribs, aseries of radially-arranged fillingebarsE guided in radial slots 8 in said plate 0, and a camplate F provided with an inner and an outer series of cam-slots adapted to act positively upon the wedge-bars and upon the sections of the core respectively, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

. JAMES WM. BONTA. WVitnesses:

BURT NEGLEY, W. B. BUCHANAN. 

